I havent actually done any code for this, was searching on internet and found this article:
http://iamzed.com/jquery/showhidediv.html
Was thinking, for our purposes…
Part of a form we are making, normal display. is like this:

And checking the checkbox, hides the above div and shows this div..

I tried to emulate what I saw in the pictures in fiddle. It’s not styled but it has the functionality you are looking for.